Invited Paper MI-FrM5
High Frequency Nanoscale Spin Transfer Devices

Friday, October 19, 2007, 9:20 am, Room 619

Spin transfers effects become important in multilayer magnetic devices whose dimensions are below 100 nm. The transfer of electron spin momentum can induce switching of magnetic layers or microwave precession of the magnetization. Spin transfer, coupled with giant magnetoresistance and tunneling magnetoresistance, can be used to develop new types of magnetic random access memory (SpinRAM), spin transfer nano-oscillators (STNOs), and spin transfer nano-detectors (STNDs). In this talk I will review high-speed spin transfer switching in nanoscale magnetic SpinRAM devices and the effects of thermal fluctuations and defects on the switching process. Next, I will present data on the linewidths, tunability, and phase control of STNOs, including data for both single domain oscillators and vortex oscillators. STNOs and STNDs have the advantage of small size, high tunability, broad frequency range (2 GHz to 100 GHz), and CMOS compatibility. However, there are intrinsic limitations in the linewidth due to thermal fluctuations, limitations due to the required applied fields, and limitations due to the sensitivity to nanoscale defects and patterning. I will discuss these challenges and the progress made towards making practical spin transfer devices for use in high-frequency communication and signal processing applications.